It's been said that we know more about space than we do about our own ocean, and now a group of scientists have quantified what sea creatures we may still not know of. After compiling an open access, online database of known marine species with the help of more than 270 experts, researchers estimate that the briny depths may be home to a total of one million species, with one third of them potentially remaining entirely unknown. Of the grand total, humans have described roughly 226,000 -- more than 20,00 of which in the past decade -- with another 65,000 tucked away in collections awaiting a write-up. Since previous estimates have been based on rates of species identification and other factors, these latest figures are considered more accurate. The effort's researchers hope that this data will be used as a reference for extinction rates and conservation. Hit the first source link below to dig through the compendium, aptly-named the World Register of Marine Species, for yourself.